


Oral Training

by Askellie (NadaNine)



Category: Undertale (Video Game)
Genre: Aftercare, Bondage, Collars, Come Marking, Dirty Talk, Dom/sub, Gags, Incest, M/M, Oral Sex, Painplay, Pretended dub-con (it's all consensual), Rough Sex, Sexual Roleplay
Language: English
Status: Completed
Published: 2018-07-04
Updated: 2018-07-04
Packaged: 2019-06-05 03:24:56
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,324
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15161501
Author URL: https://archiveofourown.org/users/NadaNine/pseuds/Askellie
Summary: To Sans, there's nothing better than testing his brother's patience and his temper. Papyrus always makes him pay for it in the most satisfying of ways.





	Oral Training

Sans’s timing couldn’t have been more perfect. As he walked into the kitchen, Papyrus was rifling through the bottom draw, long legs splayed out for balance, his tailbone high in the air. Sans took just a moment to appreciate the view – the way tight leather flexed over Papyrus’s sacrum, the heels on his boots giving the illusion of menace as well as elegance – before sneaking forward and copping an unabashed feel of his brother’s irresistibly vulnerable backside.

The girlish, outraged shriek of indignation Papyrus made was so very worth it.

But Papyrus was quick on his feet, lurching upward and spinning around to plant his back against the counter, staring at Sans with wide sockets. “You…unbelievable shithead, did you just GROPE me?”

Sans adopted his most guileless expression, making a show of looking around. “Gee, Boss, there’s no one else here, so…yeah, I guess that must have been me.”

Papyrus’s expression turned dark. Sans held his grin in place, giving a little shiver of anticipation, and wasn’t at all disappointed when Papyrus lunched forward, gauntleted fists closing around his throat. He lifted Sans with effortless, infuriated strength, slamming the smaller skeleton back against the doorframe. Sans’s skull cracked back against the wood, sending deliciously dizzying aftershocks down his spine.

“You despicable, unbearable, misbehaving asshole!” Each word was punctuated with a sharp jerk of the chokehold, rattling Sans’s bones. “How _dare_ you! I did not give you permission to touch me!”

Sans wheezed, his feet kicking uselessly at the air. Even at arms length he could feel the rage pouring off Papyrus like a furnace heat. He might have honestly worried that maybe he’d gone a step too far if he couldn’t also detect the pepper-cinnamon scent of arousal underlying his brother’s fury. The smell went straight to his crotch, where magic had already taken up eager residence over his pubic mound.

“Boss,” he groaned, scrabbling uselessly at his brother’s fist, torn between the powerful reflex to free himself and the even stronger instinct warning him that Boss would make him regret it. The delicious, dangerous high made his magic roil under his clothes. One more hard shove against the doorframe made it coalesce with almost painful suddenness, new nerve endings bursting into life already primed and over-sensitive. His cock swelled against the inside of his shorts, the rough fabric making him whimper. Papyrus’s gaze dropped very deliberately downward, taking blatant notice of this new development.

“And now you think I’m going to reward you for bad behavior?” Papyrus growled, ruthlessly shoving his knee up between Sans’s femurs. The smaller skeleton yelped at the pressure, grinding helplessly down. God, the hard, unforgiving bones of Papyrus’s leg felt so good. Sans could get off easily like this, flailing and choking, head spinning from the lack of air and the rough handling. He wanted it so badly. Desperate noises poured out of his mouth, trying to spur Papyrus on.

But of course Papyrus wasn’t in a generous mood after Sans’s little stunt. He made a sound of disgust, and with a grunt that was probably more for effect than effort, threw Sans into the living room with enough force to make him tumble across the floor.

It was a very precise throw, however careless it might have looked. All of Sans’s momentum was lost in the friction of the carpet scraping against his bones, leaving a warm, burning sensation in its wake. He sat up only to find Papyrus standing over him, putting every inch of height difference between them to good use by looming fearsomely.

“On your knees,” Papyrus snapped, his voice sharp as a whip. “And apologise, you filthy mutt.”

Obligingly, Sans rolled onto his knees, but despite the way his soul was quivering from the dangerous expression on Papyrus’s face, his grin remained unrepentant. “Sorry, Boss. ”

“Oh you will be,” Papyrus promised darkly, his heavy hand snatching Sans by the nape and shoving him face-first into the floor. The carpet didn’t do much to cushion the blow, and while Sans’s skull was still ringing, Papyrus had no trouble lashing the smaller skeleton’s forearms behind his back with the thick strap of his own belt.

“Fuuuuck,” Sans whined, straining against the leather. Without his arms for balance, he couldn’t even successfully pry himself off the floor, which gave Papyrus ample opportunity to yank his shorts off, baring Sans’s pelvis. “Hngh! Boss!”

Sans tried to jerk against his brother’s hands, but Papyrus deftly avoided touching him anywhere he might have enjoyed it. Sans growled a curse into the carpet, only to choke with an undignified squawk as Papyrus clipped his leash to Sans’s collar and roughly dragged Sans back onto his knees.

“If you’re so interested in my pelvis,” Papyrus said, primly taking a seat on a nearby stool, “perhaps you should become better acquainted with it.”

He tugged the leash, jerking Sans’s face towards his crotch. With his belt already removed, Papyrus’s pants were already hanging open, revealing the heated crimson magic roiling over his own bones, licking like flames over his pubis. It was strangely beautiful and undeniably erotic, but Sans made a face, trying to turn his head away.

“Ugh, come on, Boss…”

Sans didn’t like giving oral. It was way too much work for not enough benefit, and he liked to have his mouth free so he didn’t feel so embarrassingly, arousingly helpless. He hated how much he liked it when he was gagged and bound, an impotent receptacle for his brother’s pleasure – a silenced sex toy, a writhing, dripping cock-sleeve for his brother to fuck.

And he hated that Papyrus knew it, and took a distinctive pleasure in gagging Sans whenever possible.

“Why don’t you just fuck me?” he tried hopefully, attempting to give an enticing wiggle. His shaft bobbed heavily between his legs, and he hid a wince. Normally he wouldn’t favour being fucked – at least not until Boss really got him begging – but he was uncomfortably aware of how neglected his cock was starting to feel. With his hands free, he couldn’t touch it himself, and he doubted Boss was going to oblige him so his opportunities for getting off were starting to look dim.

A cruel hand yanked on the leash, pulling Sans down into Papyrus’s lap again. “Who’s giving the orders here, you little shit? Get your mouth busy unless you want me to put you outside with the rest of the dogs.

Sans shivered. Boss would do it too, leaving Sans out on the porch, pants-less and aroused, knee-deep in snow. With a reluctant grumble he opened his mouth and let his tongue lap along the groove of Papyrus’s pubic symphysis, tasting iron-heat and spicy musk. Immediately he could feel pressure pushing its way between his teeth, and quickly had to widen his jaw to accommodate the thick shape of his brother’s length forcing its way to the back of his throat.

“Huuah,” he moaned in complaint, careful to keep his teeth from scraping the delicate ecto-flesh, having to gape his mouth even wider. With his tongue flattened to the floor of his mouth, there was no way to stop saliva from dripping down his chin. He’d barely taken in half of his brother’s cock, and already he could feel it bulging warningly at the back of his throat, making him reluctant to take it any further.

“You’re miserable at this,” Papyrus groused, one clawed hand pressing on the back of Sans’s skull. “Take it deeper, you filthy slut!”

“Urk!” The head of Papyrus’s cock stretched out the back of Sans’s throat, straining against its natural boundaries before another hard push stuffed it down Sans’s esophagus. Thankfully his intangible innards didn’t include a gag reflex, nor did skeletons truly need to breathe, but it was dizzyingly uncomfortable – a tight, straining pressure that made his mouth feel violated and his head feel full.

“Hnnnnngh…” His eyelights turned fuzzy, hazing with pleasure. His cock seemed to throb in time with the pulses he could feel from Papyrus’s magic. His face burned with humiliation as a hot trickle of pre-ejaculate leaked from the tip of his phallus and down his length, exposing just how much he enjoyed his brother’s harsh treatment.

“That’s it. You like this, don’t you, my sweet little bitch?” Papyrus asked him, his scowl now turning into a wicked smirk. “You like it when I fuck your dirty mouth. You’re such an eager whore, brother.”

Sans whimpered, desperately trying to suck around Papyrus’s cock, hoping to pleasure him enough to earn some mercy, but it was so huge and so far down his throat he only managed to pitifully flex his throat muscles in a poor imitation of proper suction.

“I’m going to fill up your empty skull with my cum, pet,” Papyrus promised generously, his voice taking on a rough, animalistic growl as he ground his cock against the back of Sans’s cranium. “Look at you, choking on your brother’s cock, loving every second of it. I’m going to fill you up with my seed until the brains are literally fucked out of you. You’ll be tasting me for a month, and every time you bite into one of those disgusting burgers you like I’ll be on your tongue reminding you of what a good-for-nothing slut you are.”

Sans’s head spun with his brother’s filthy words, making him unbearably hard. His cock with a spike of agonised need rooted in his pelvis, and he thoughtlessly canted his hips, seeking any kind of relief. Papyrus’s hard, booted heel came down on his illium, pressing his tailbone back to the floor.

“Not yet,” Papyrus warned. “Not until you satisfy me, brother. If you want me to fuck you just like you asked, you better suck like your life depends on it, because I’m not going to be finished with your mouth until you’ve got cum pouring out your eye-sockets.”

Sans flinched, toes curling, spine stiffening, and his throat constricting fiercely around Papyrus. If there was any warning, he must have missed it entirely because suddenly the pressure inside him increased twofold as a hot stream of ejaculate was jettisoned down his throat. His frenzied choking prompted Papyrus to pull back slightly so instead Sans caught the liquid more properly in his mouth. It painted his tongue, downing him in its spicy, bitter taste, and without thinking Sans gulped it down.

“Did you swallow it?” Papyrus asked, dragging Sans’s sweaty face up by the leash. The tip of his cock was still lodged between the smaller skeleton’s teeth, so an answer was impossible,”but he didn’t seem to expect one. He only made an amused, chiding sound. “Greedy bitch. Now we have to start over.”

Sans tried to blurt a protest, ready to beg, to cry, anything, so long as Papyrus would touch him instead, but his skull was shoved back down onto Papyrus’s cock and all that came out was a weak and wet sounding sob.

 

* * *

 

Sans lay sprawled out on the couch, limp, dazed and thoroughly content. His pelvis ached deliciously, still throbbing with the punishment Boss had given it after he’d finally finished filling up every cavity in Sans’s skull.

“Tch,” Boss grunted. A soft, damp cloth scrubbed over Sans’s cheeks, cleaning away sweat, tears and copious trails of cum. “Still a filthy dog. You really never learn.”

Sans made a gurgling, pleased sound, soaking up the grudging fondness in Papyrus’s voice. He managed to catch the collar of his brother’s jacket and yank him downward, opening his mouth to plant wet, fervent kisses over Papyrus’s jaw. For a moment Papyrus cringed at the sloppiness of it, threatening to pull away, but the sweet, yearning sounds Sans made drew him back. He parted his own sharp teeth, letting their tongues tangle briefly in a hungry fight for dominance that Papyrus readily one. He plundered Sans’s mouth, tasting his own spicy magic on his brother’s tongue. It was a decidedly pleasing achievement.

“Enough,” he said when Sans tried to deepen the kiss, his body arching yieldingly, trying to tempt Papyrus to linger. “I don’t want your mess on my clothes.”

Sans pouted, although the gesture was weakened by a wince as his expression shifted too quickly. Papyrus made a vexed sound, wordlessly hooking his fingers under Sans’s mandible and letting a small trickle of healing magic sooth the strain he’d put on the smaller skeleton’s jaw. Not enough to suggest he was coddling Sans or any similarly embarrassing sentiment, but enough to hide the weakness from anyone other than himself.

“Better?” Papyrus asked gruffly. Sans nodded eagerly, which only made Papyrus frown deepen. “Say ‘yes, Boss’.”

“Yes, Boss,” Sans repeated obediently, but as expected, the words sounded weak and rough, reflecting the harsh treatment of his throat. There was also a thick, clogged quality to his voice. If Papyrus peered into Sans’s eye-sockets from the right angle, he could see a considerable pool of magic still sitting in his skull.

“I told you, you didn’t need to keep that,” Papyrus chided him, exasperated. Honestly, Sans should know better than to adhere to anything Papyrus said in the context of a scene. “Your voice will recover faster if you get rid of it.”

“Don’t wanna,” Sans replied belligerently, but his gaze on Papyrus was full of adoration. “I like it. Wanna keep tasting you.”

Papyrus turned his head to hide the startled blush that threatened to creep along his cheekbones. When he was sure he had it mastered, he turned back with an appropriately scolding expression. “Well at the very least, you should clean it off the rest of you. I don’t understand how you can endure being so disgusting.”

Sans made an indifferent sound, but obligingly reached up so Papyrus could lift him from the couch. They both knew when Papyrus said _you should_ he really meant _I will_ , and Sans curled up trustingly in his arms as Papyrus carried him towards the bathroom.


End file.
